JP2013165367A - Piezoelectric device and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric device where a formation region of a joint material is narrow, and to provide a manufacturing method of the piezoelectric device.SOLUTION: A piezoelectric device (100) includes: a piezoelectric vibration piece (130) which is subject to application of a voltage thereby vibrating; a base plate (120) on which the piezoelectric vibration piece is placed; a lid plate (110) joined to the base plate and sealing the piezoelectric vibration piece; and a joining material (142) joining the base plate to the lid plate. The lid plate and the base plate respectively have annular joining surfaces (112, 122), each of which has a predetermined width to which the joining material may be applied, and a width of an area where the joining material is joined to the joining surface of at least one of the lid and the base plate is narrower than the predetermined width of the joining surface.

Description

  The present invention relates to a piezoelectric device having a bonding material forming region (width) narrow and a method for manufacturing the piezoelectric device.

  A piezoelectric vibrating piece that vibrates at a predetermined vibration frequency is known. The piezoelectric vibrating piece is placed in a cavity formed by a lid plate and a base plate to form a piezoelectric device. The lid plate and the base plate are bonded to each other by a bonding material. The bonding material is applied to the bonding surface of the lid plate or the base plate in a softened state, and is cured by heating.

  Since the lid plate and the base plate are bonded together in a state where the bonding material is softened, there are some problems in the manufacturing process of the piezoelectric device. For example, when the lid plate and the base plate are joined, there is a problem that the joining material spreads over the entire joining surface and further enters the cavity. When the bonding material comes into contact with the piezoelectric vibrating piece, the vibration frequency of the piezoelectric vibrating piece changes. Further, it is necessary to form a wide bonding surface so that the bonding material surely seals the inside of the cavity, and the volume in the cavity is reduced.

  On the other hand, Patent Document 1 discloses that a frame-shaped metal film is formed on a joining surface, and a low melting point and a high melting point metal ball is used as a joining material to join the lid plate and the base plate. Since the molten metal ball diffuses on the frame-like metal film, it is possible to prevent the bonding material from entering the cavity. Further, it is disclosed that sealing can be performed reliably and miniaturization is possible.

JP 2011-199230 A

  However, in patent document 1, since metal was used for the bonding material, the cost was high. Further, when a metal is used for the bonding material, it cannot be used for a piezoelectric device of a type in which electrodes are formed on the bonding surface.

  It is an object of the present invention to provide a piezoelectric device and a method for manufacturing a piezoelectric device in which a bonding material is formed by using an inexpensive material to reduce manufacturing cost and to ensure sealing of a cavity, and in which a bonding material formation region is narrow. .

  A piezoelectric device according to a first aspect includes a piezoelectric vibrating piece that vibrates by application of a voltage, a base plate on which the piezoelectric vibrating piece is placed, a lid plate that is bonded to the base plate and seals the piezoelectric vibrating piece, a base plate, A bonding material for bonding the lid plate, the lid plate and the base plate have an annular bonding surface having a predetermined width to which the bonding material can be applied, and the bonding material and the lid plate or the base plate The width at which at least one of the bonding surfaces is bonded is smaller than the predetermined width of the bonding surface.

  A piezoelectric device according to a second aspect includes a piezoelectric vibrating piece having a vibrating portion that vibrates by application of a voltage and a frame surrounding the vibrating portion, and bonded to both main surfaces of the frame of the piezoelectric vibrating piece, sealing the vibrating portion, and glass. Alternatively, a base plate and a lid plate made of quartz, and a bonding material for bonding the frame body to the base plate and the lid plate, the bonding material can be applied to the lid plate, the base plate, and the frame body. An annular joining surface having a predetermined width is provided, and a width at which the joining material and at least one of the lid plate, the base plate, and the joining surface of the frame body are joined is narrower than the predetermined width of the joining surface.

  In the piezoelectric device according to the third aspect, in the first aspect, the bonding material absorbs a laser having a predetermined wavelength, and at least one of the lid plate or the base plate transmits the laser.

  In the piezoelectric device according to the fourth aspect, in the second aspect, the bonding material absorbs a laser having a predetermined wavelength, and the lid plate and the base plate transmit the laser.

  The piezoelectric device according to the fifth aspect is 350 ° C. to 410 ° C. in which the bonding material is mixed with metal particles that absorb a predetermined wavelength or colored with a coloring material that absorbs the predetermined wavelength in the third and fourth aspects. It is a low-melting glass that melts at ° C.

  A piezoelectric device manufacturing method according to a sixth aspect includes a piezoelectric vibrating piece that vibrates by application of a voltage, a base plate on which the piezoelectric vibrating piece is placed, and a lid plate that seals the piezoelectric vibrating piece to the base plate. A method for manufacturing a device, the step of preparing a plurality of piezoelectric vibrating pieces, the step of preparing a base wafer having a plurality of base plates and a lid wafer having a plurality of lid plates, and bonding to a bonding surface of the base wafer or the lid wafer A step of applying a material, a temporary curing step of heating the applied bonding material to temporarily cure the bonding material, a mounting step of mounting the piezoelectric vibrating piece on the base plate, and the piezoelectric vibrating piece mounted A step of superimposing the lid wafer on the base wafer, and a bonding step of irradiating the bonding material with a laser having a predetermined wavelength to melt the bonding material and bonding the base wafer and the lid wafer, At least one of Ddoueha or base wafer is transmitted through the laser of a predetermined wavelength, bonding material generates heat by absorbing the laser of a predetermined wavelength.

  A method for manufacturing a piezoelectric device according to a seventh aspect includes a step of preparing a piezoelectric wafer including a plurality of piezoelectric vibrating pieces having a vibrating portion that vibrates by application of a voltage and a frame surrounding the vibrating portion, and a plurality of base plates A step of preparing a base wafer and a lid wafer having a plurality of lid plates, a step of applying a bonding material to both main surfaces of the frame, and a temporary curing step of heating the applied bonding material to temporarily cure the bonding material And the base wafer and the piezoelectric wafer are overlapped, and the bonding material is melted by irradiating a bonding material disposed between the base wafer and the piezoelectric wafer by irradiating a laser having a predetermined wavelength with the base wafer and the piezoelectric wafer. The first bonding step of bonding the wafer, the lid wafer and the piezoelectric wafer are overlapped, and the bonding material disposed between the lid wafer and the piezoelectric wafer is irradiated with a laser to melt the bonding material. It comprises a second bonding step of bonding the lid wafer and the piezoelectric wafer, the. The bonding material absorbs the laser and generates heat, and the lid wafer and the base wafer transmit the laser.

  In the sixth aspect and the seventh aspect, the piezoelectric device manufacturing method according to the eighth aspect comprises a low-melting glass in which the bonding material melts at 350 ° C. to 410 ° C.

  The piezoelectric device manufacturing method according to the ninth aspect includes a cutting step in which the piezoelectric device is individually divided by cutting the lid wafer and the base wafer, and at least the bonding material is not applied to the area to be cut of the lid wafer.

  According to the piezoelectric device and the manufacturing method of the piezoelectric device of the present invention, the formation region of the bonding material can be narrowed.

1 is an exploded perspective view of a piezoelectric device 100. FIG. (A) is AA sectional drawing of FIG. FIG. 2B is an enlarged cross-sectional view of the piezoelectric device 100 in which the dotted line region 171 in FIG. 3 is a flowchart illustrating a method for manufacturing the piezoelectric device 100. It is a top view of the piezoelectric wafer W130. It is a top view of the base wafer W120. It is a top view of the lid wafer W110. (A) is a partial cross-sectional view of the base wafer W120 on which the piezoelectric vibrating piece 130 is placed. FIG. 6B is a partial cross-sectional view of the base wafer W120, the piezoelectric vibrating piece 130, and the lid wafer W110. FIG. 6C is a partial cross-sectional view of the base wafer W120, the piezoelectric vibrating piece 130, and the lid wafer W110 in which the bonding material 142 is irradiated with the laser 151. FIG. 3A is a cross-sectional view of the piezoelectric device 200. FIG. FIG. 8B is an enlarged cross-sectional view of the dotted line region 172 in FIG. (A) is an enlarged plan view of the base wafer W120 to which the bonding material 141 is applied. FIG. 6B is a partial cross-sectional view of the base wafer W120, the piezoelectric vibrating piece 130, and the lid wafer W110. FIG. 6C is a partial cross-sectional view of the base wafer W120, the piezoelectric vibrating piece 130, and the lid wafer W110 in which the bonding material 142 is irradiated with the laser 151. 3 is an exploded perspective view of a piezoelectric device 300. FIG. (A) is CC sectional drawing of FIG. (B) is FF sectional drawing of FIG. 5 is a flowchart illustrating a method for manufacturing the piezoelectric device 300. It is a top view of the piezoelectric wafer W330. (A) is a fragmentary sectional view of the piezoelectric wafer W330 with the bonding material 142 applied thereto. FIG. 4B is an enlarged plan view of the surface at the −Y′-axis side of the piezoelectric wafer W <b> 330 to which the bonding material 142 is applied. It is a top view of the base wafer W320. (A) is a fragmentary sectional view of piezoelectric wafer W330 and base wafer W320 which were piled up mutually. FIG. 6B is a partial cross-sectional view of the piezoelectric wafer W330 and the base wafer W320 bonded to each other. (A) is a fragmentary sectional view of piezoelectric wafer W330, base wafer W320, and lid wafer W310 to which piezoelectric wafer W330 and lid wafer W310 are joined. FIG. 5B is a partial cross-sectional view of the piezoelectric wafer W330, the base wafer W320, and the lid wafer W310 having electrodes formed on the base wafer W320. (A) is CC sectional drawing of FIG. 10 as the piezoelectric device 400. FIG. (B) is FF sectional drawing of FIG. 10 as the piezoelectric device 400. FIG. (A) is an enlarged plan view of the surface on the + Y′-axis side of the piezoelectric wafer W <b> 330 coated with the bonding material 142. FIG. 4B is an enlarged plan view of the surface at the −Y′-axis side of the piezoelectric wafer W <b> 330 to which the bonding material 142 is applied. FIG. 4A is a partial cross-sectional view of the lid wafer W310, the piezoelectric wafer W330, and the base wafer W320 in which the piezoelectric wafer W330 and the lid wafer W310 are bonded. FIG. 4B is a partial cross-sectional view of the lid wafer W310, the piezoelectric wafer W330, and the base wafer W320 in which electrodes are formed on the base wafer W320.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings. It should be noted that the scope of the present invention is not limited to these forms unless otherwise specified in the following description.

(First embodiment)
<Configuration of Piezoelectric Device 100>
FIG. 1 is an exploded perspective view of the piezoelectric device 100. The piezoelectric device 100 is formed by a piezoelectric vibrating piece 130, a lid plate 110, and a base plate 120. The base plate 120 is made of an insulating material such as ceramic, quartz, and glass. The lid plate 110 is made of a material that transmits a laser having a predetermined wavelength, which will be described later, such as quartz and glass. Further, for example, an AT-cut crystal vibrating piece is used for the piezoelectric vibrating piece 130. The AT-cut quartz crystal resonator element has a principal surface (YZ plane) inclined with respect to the Y axis of the crystal axis (XYZ) by 35 degrees 15 minutes from the Z axis in the Y axis direction around the X axis. In the following description, the new axes tilted with respect to the axial direction of the AT-cut quartz crystal vibrating piece are used as the Y ′ axis and the Z ′ axis. That is, in the piezoelectric device 100, the long side direction of the piezoelectric device 100 is described as the X-axis direction, the height direction of the piezoelectric device 100 is defined as the Y′-axis direction, and the direction perpendicular to the X and Y′-axis directions is described as the Z′-axis direction. .

  In the piezoelectric device 100, the piezoelectric vibrating piece 130 is placed in the recess 121 formed on the + Y′-axis side of the base plate 120. Further, the lid plate 110 is bonded to the surface on the + Y′-axis side of the base plate 120 so as to seal the recess 121 on which the piezoelectric vibrating piece 130 is placed, so that the piezoelectric device 100 is formed.

  The piezoelectric vibrating piece 130 has excitation electrodes 131 formed on surfaces on the + Y′-axis side and the −Y′-axis side. From the excitation electrode 131 on the + Y′-axis side, an extraction electrode 132 is formed that extends in the −X-axis direction and extends to the surface on the −Y′-axis side through the side surface on the + Z′-axis side. Further, from the excitation electrode 131 formed on the surface at the −Y′-axis side, the extraction electrode 132 is led out to the corner portion at the −Z′-axis side on the −X-axis side.

  The base plate 120 has an annular joint surface 122 on the surface on the + Y′-axis side and a recess 121 that is recessed from the joint surface 122 to the −Y′-axis side. The lid plate 110 is bonded to the bonding surface 122 via a bonding material 142 (see FIG. 2), and the piezoelectric vibrating piece 130 is placed in the recess 121. A connection electrode 123 that is electrically connected to the lead electrode 132 of the piezoelectric vibrating piece 130 and the conductive adhesive 141 (see FIG. 2) is formed in the recess 121, and the −Y ′ axis of the base plate 120 is formed. A pair of mounting terminals 125 are formed on the side surface. The connection electrode 123 is electrically connected to the mounting terminal 125 via a through electrode 124 that penetrates the base plate 120.

  The lid plate 110 includes an annular joint surface 112 that is joined to the joint surface 122 of the base plate 120 via a joint material 142 on the surface on the −Y ′ axis side, and a recess that is recessed from the joint surface 112 to the + Y ′ axis side. 111 is formed.

  FIG. 2A is a cross-sectional view taken along the line AA in FIG. The piezoelectric device 100 is formed by mounting the piezoelectric vibrating piece 130 in the recess 121 of the base plate 120 and bonding the bonding surface 112 of the lid plate 110 to the bonding surface 122 of the base plate 120 via the bonding material 142. ing. A cavity 101 surrounded by the base plate 120 and the lid plate 110 is formed inside the piezoelectric device 100. As the bonding material 142, a material that absorbs and melts a laser having a predetermined wavelength is used. Examples of such a bonding material 142 include a low-melting glass containing a pigment that absorbs a laser having a predetermined wavelength. A connection electrode 123 is formed in the recess 121 of the base plate 120, and the connection electrode 123 and the extraction electrode 132 of the piezoelectric vibrating piece 130 are electrically connected by a conductive adhesive 141. Further, the through electrode 124 penetrating the base plate 120 electrically connects the connection electrode 123 and the mounting terminal 125. That is, the excitation electrode 131 of the piezoelectric vibrating piece 130 is electrically connected to the mounting terminal 125.

  FIG. 2B is an enlarged cross-sectional view of the piezoelectric device 100 in which the dotted line region 171 in FIG. In the piezoelectric device 100, a bonding material 142 is formed on the entire bonding surface 122 of the base plate 120. That is, when the width of the joining surface 122 of the base plate 120 is the width WS3, the joining material 142 and the joining surface 122 are joined with the width WS3. On the other hand, on the bonding surface 112 of the lid plate 110, the bonding material 142 is not formed on the inner peripheral side of the bonding surface 112 (the -X axis side of the bonding surface 112 in FIG. 2B). A bonding material 142 is formed on the outer peripheral side (the + X axis side of the bonding surface 112 in FIG. 2B). That is, assuming that the width of the bonding surface 112 of the lid plate 110 is the width WS1, and the bonding material 142 and the bonding surface 112 are bonded with the width WS2, the width WS1 is formed wider than the width WS2.

<Method for Manufacturing Piezoelectric Device 100>
FIG. 3 is a flowchart showing a method for manufacturing the piezoelectric device 100. A method for manufacturing the piezoelectric device 100 will be described below with reference to the flowchart of FIG.

  In step S101, the piezoelectric vibrating piece 130 is prepared. Step S101 is a process of preparing a plurality of piezoelectric vibrating pieces 130. The piezoelectric vibrating piece 130 is prepared at a time by forming the plurality of piezoelectric vibrating pieces 130 on the piezoelectric wafer W130.

  FIG. 4 is a plan view of the piezoelectric wafer W130. In the piezoelectric wafer W <b> 130, the outer shape of the plurality of piezoelectric vibrating pieces 130 is formed by forming through holes 161 by etching. Each piezoelectric vibrating piece 130 is connected to the piezoelectric wafer W <b> 130 via a connecting portion 162. Each piezoelectric vibrating piece 130 is formed with an excitation electrode 131 and an extraction electrode 132. Each piezoelectric vibrating piece 130 is separated from the piezoelectric wafer W130 when the connecting portion 162 is broken.

  In step S201, a base wafer W120 is prepared. Step S201 is a process of preparing a base wafer W120 having a plurality of base plates 120.

  FIG. 5 is a plan view of the base wafer W120. A plurality of base plates 120 are formed on the base wafer W120. In FIG. 5, a scribe line 163 is shown at the boundary between the base plates 120 adjacent to each other. The scribe line 163 indicates a line to be cut when the wafer is cut in a cutting process described later. Each base plate 120 formed on the base wafer W120 has a recess 121 and a bonding surface 122 on the surface at the + Y′-axis side. A connection electrode 123 is formed in the recess 121. A mounting terminal 125 (see FIG. 2A) is formed on the surface of each base plate 120 on the −Y′-axis side, and the connection electrode 123 and the mounting terminal 125 are electrically connected to each other via the through electrode 124. Connected.

  In step S202, the bonding material 142 is applied to the bonding surface 122 of the base wafer W120. Step S202 is a process of applying the bonding material 142 to the bonding surface 122 of the base wafer W120. For the bonding material 142, for example, low melting point glass is used. The application of the bonding material 142 to the bonding surface 122 can be performed by screen printing, for example. Screen printing is a method of printing by forming a screen having an opening of a specific shape on the base wafer W120 and extruding the bonding material 142 from the opening. In step S202, for example, a screen having an opening in the shape of the bonding surface 122 is formed on the base wafer W120, and the bonding material 142 can be applied to the bonding surface 122 by extruding the bonding material 142 from the opening.

  In step S203, the bonding material 142 is temporarily cured. Step S203 is a temporary curing process. In step S202, the low-melting glass as the bonding material 142 is in a paste form having a certain degree of viscosity and fluidity. In step S203, the bonding material 142 is heated and cured. Accordingly, it is possible to prevent the binder, the solvent, and the like in the bonding material 142 from escaping and the gas and the like from being mixed into the piezoelectric device 100. In addition, these gases may become bubbles and cause unevenness in the bonding between the base wafer W120 and the lid wafer W110. However, by removing these gases to some extent before bonding the wafers, the gas bubbles are reduced. Uneven bonding caused by this can be prevented.

  In the temporary curing step, for example, when a vanadium-based low-melting glass having a transition point of 295 ° C. and a softening point of around 350 ° C. is used for the bonding material 142, first, the temperature is 110% to 115% of the transition point. The temperature is raised to 325 ° C. to 340 ° C., and this temperature is maintained for 30 minutes. Subsequently, the temperature is raised to 370 ° C. to 390 ° C., which is 125% to 133% of the transition point. After being held for 10 minutes in this state, the bonding material 142 is cooled and cured.

  In step S301, a lid wafer W110 is prepared. Step S301 is a step of preparing a lid wafer W110 having a plurality of lid plates 110. Step S301 can be manufactured without considering the order of manufacturing with respect to Step S101 and Step S201.

  FIG. 6 is a plan view of the lid wafer W110. A plurality of lid plates 110 are formed on the lid wafer W110. In FIG. 6, a scribe line 163 is illustrated at the boundary between the lid plates 110 adjacent to each other. Each lid plate 110 has a recess 111 formed on the surface at the −Y′-axis side, and a bonding surface 112 is formed so as to surround the recess 111.

  In step S401, the piezoelectric vibrating piece 130 is placed on the base wafer W120. Step S <b> 401 is a placement process for placing the piezoelectric vibrating piece 130 on the base plate 120.

  FIG. 7A is a partial cross-sectional view of the base wafer W120 on which the piezoelectric vibrating piece 130 is placed. FIG. 7A shows a cross-sectional view including a cross section BB in FIG. In FIG. 7A, a bonding material 142 is applied to the bonding surface 122 by screen printing. The bonding material 142 is cured by the temporary curing process in step S203. In FIG. 7A, the piezoelectric vibrating piece 130 is placed in the recess 121 via the conductive adhesive 141.

  In step S402, the lid wafer W110 is overlaid on the base wafer W120. Step S402 is a process of superimposing the lid wafer W110 on the base wafer W120 on which the piezoelectric vibrating piece 130 is placed.

  FIG. 7B is a partial cross-sectional view of the base wafer W120, the piezoelectric vibrating piece 130, and the lid wafer W110. FIG. 7B shows a state in which the lid wafer W110 is superimposed on the base wafer W120. In FIG. 7B, the lid wafer W110 is superimposed on the + Y′-axis side of the cured bonding material 142 formed on the + Y′-axis side surface of the bonding surface 122 of the base wafer W120. The bonding material 142 is in contact with the bonding surface 112 of the lid wafer W110 but is not bonded.

  In step S403, the base wafer W120 and the lid wafer W110 are bonded by laser. Step S403 is a bonding process in which the bonding material 142 is irradiated with a laser having a predetermined wavelength to melt the bonding material 142 and bond the base wafer W120 and the lid wafer W110.

  FIG. 7C is a partial cross-sectional view of the base wafer W120, the piezoelectric vibrating piece 130, and the lid wafer W110 in which the bonding material 142 is irradiated with the laser 151. In FIG. 7C, the bonding material 142 is locally heated by the laser 151, and the bonding material 142 is melted and bonded to the bonding surface 111 of the lid wafer W110. The laser 151 emitted from the laser oscillator 152 is reflected by the galvanometer mirror 153 and applied to the bonding material 142. The beam diameter of the laser 151 is adjusted according to the width of the bonding surface 112, and the irradiation position of the laser 151 is determined by the position and angle of the galvanometer mirror 153. Further, since the laser 151 passes through the lid wafer W110 and is irradiated onto the bonding material 142, the lid wafer W110 is formed of a material that transmits the laser 151, such as crystal and glass. The bonding process is performed while the lid wafer W <b> 110 is pressed by the bonding material 142, but only a part of the bonding material 142 is melted by the laser 151, so that the bonding material 142 enters the cavity 101 of the piezoelectric device 100. There is no invasion.

  As the laser 151, for example, a YAG (Yttrium Aluminum Garnet) laser can be used. Since the fundamental wavelength of the YAG laser is 1064 μm, the bonding material 142 in this case has chromium (Cr), molybdenum (Mo), iron (Fe), or these elements having a high laser absorptance of this wavelength. A low-melting glass containing stainless steel particles containing can be used. In addition, when an SHG (Second Harmonic Generation) laser is used, copper (Cu) having a high absorptance with respect to light of 532 nm which is the oscillation wavelength of the laser, or a pigment having a high absorptance in the entire visible light Such as carbon black can be included in the low-melting glass. For example, a low melting glass that melts at 350 ° C. to 410 ° C. can be used as the bonding material 142, but when the low melting glass contains these elements and particles, these elements or particles absorb the laser and generate heat. In addition, the bonding material 142 can be efficiently melted.

  In step S404, the base wafer W120 and the lid wafer W110 are cut. The cutting is performed by cutting the wafer along the scribe line 163. Thereby, the piezoelectric device 100 is divided into individual pieces.

  In the piezoelectric device 100, by using an inexpensive low-melting glass for the bonding material 142, the manufacturing cost can be kept lower than when a metal film is formed on the bonding surface and the base plate and the lid plate are bonded. Even when a low-melting glass is used as the bonding material 142, it takes time to raise the temperature of the entire space in which the wafer is placed in order to bond the low-melting glass to the lid wafer, but the low-melting glass is heated using a laser. By doing so, the temperature raising time of the low melting point glass can be shortened, and the bonding time of the lid wafer can be shortened. Further, in the piezoelectric device 100, since the bonding material 142 is locally heated by the laser 151 and only a part of the bonding material 142 is melted, the bonding material 142 does not flow into the cavity 101 and the piezoelectric vibration is generated by the bonding material 142. The vibration of the piece 130 is not hindered. In the piezoelectric device 100, the bonding material 142 is locally irradiated with the laser 151, whereby the bonding material and the lid wafer can be reliably bonded, and the cavity can be sealed so as not to cause bonding failure. . For this reason, the width of the joint surface, which has been widened to ensure sealing, can be narrowed, and the inside of the cavity can be made wider, or the outer shape of the piezoelectric device can be made smaller. Moreover, since the formation region of the bonding material can be narrowed, the amount of the bonding material used can be reduced, and the manufacturing cost can be reduced.

  The piezoelectric device may bond the lid wafer and the base wafer by applying a bonding material to the bonding surface of the lid wafer and irradiating the bonding material with a laser through the base wafer. However, in this case, the mounting terminal formed on the base wafer is formed after the bonding of the lid wafer and the base wafer, or the mounting terminal is formed so as not to overlap the region of the bonding material irradiated with the laser. .

<Configuration of Piezoelectric Device 200>
In the cutting of the base wafer and the lid wafer in step S404 shown in FIG. 3, the bonding material is not formed on the scribe line, so that the cutting can be performed more easily. Hereinafter, the piezoelectric device 200 that can easily cut the wafer will be described. In the following description, the same parts as those of the piezoelectric device 100 are denoted by the same reference numerals and description thereof is omitted.

  FIG. 8A is a cross-sectional view of the piezoelectric device 200. The piezoelectric device 200 differs from the piezoelectric device 100 only in the formation position of the bonding material 142, and the other configuration is the same as that of the piezoelectric device 100.

  FIG. 8B is an enlarged cross-sectional view of the dotted line region 172 in FIG. In the piezoelectric device 200, the bonding material 142 is not formed on the inner peripheral side 112 a and the outer peripheral side 112 b of the bonding surface 112 of the lid plate 110. Therefore, the width WS1 of the bonding surface 112 is formed wider than the width WS2 where the bonding material 142 and the bonding surface 112 are bonded. Further, the bonding material 142 is not formed on the outer peripheral side 122 b of the bonding surface 122 of the base plate 120. Therefore, the width WS3 of the bonding surface 122 is formed wider than the width WS4 where the bonding material 142 and the bonding surface 122 are bonded.

<Method for Manufacturing Piezoelectric Device 200>
Also in the piezoelectric device 200, the piezoelectric device 200 can be manufactured by the same procedure as the flowchart shown in FIG. Hereinafter, a method of manufacturing the piezoelectric device 200 will be described with reference to the flowchart of FIG. In the following description, only portions different from the piezoelectric device 100 will be described, and description of portions similar to the method for manufacturing the piezoelectric device 100 will be omitted.

  FIG. 9A is an enlarged plan view of the base wafer W120 to which the bonding material 141 is applied. FIG. 9A shows a state in which the bonding material 142 is applied to the bonding surface 122 of the base wafer W120 by screen printing in step S202 of FIG. 3 on the base wafer W120 of FIG. The bonding material 142 is applied to the periphery of the bonding surface 122 of the base wafer W120 adjacent to the recess 121, and is not applied to the scribe line 163. By applying the bonding material 142 by screen printing, the bonding material 142 is accurately applied to a position that does not enter the recess 121 and does not overlap the scribe line 163.

  FIG. 9B is a partial cross-sectional view of the base wafer W120, the piezoelectric vibrating piece 130, and the lid wafer W110. FIG. 9B shows a state in which the lid wafer W110 is overlaid on the base wafer W120 in step S402 of FIG. The bonding material 142 is formed so as not to overlap the scribe line 163 in the Y′-axis direction. Since the bonding material 142 shown in FIG. 9B is cured, the bonding material 142 does not diffuse on the scribe line 163 and into the cavity 101 even when the lid wafer W110 is stacked on the bonding material 142.

  FIG. 9C is a partial cross-sectional view of the base wafer W120, the piezoelectric vibrating piece 130, and the lid wafer W110 in which the bonding material 142 is irradiated with the laser 151. FIG. 9C shows a state in which the base wafer W120 and the lid wafer W110 are bonded by the laser 151 in step S403 of FIG. The beam diameter of the laser 151 is adjusted in accordance with the width at which the bonding material 142 is bonded to the lid wafer W110, and the laser 151 passes through the lid wafer W110 and is irradiated onto the bonding material 142. Since the bonding material 142 is locally heated by the laser 151, even when the bonding material 142 is melted, the bonding material 142 does not diffuse onto the cavity 101 and the scribe line 163.

  In step S404 in FIG. 3, the base wafer W120 and the lid wafer W110 are cut. However, since the bonding material 142 is not formed on the scribe line 163 in the piezoelectric device 200, the cutting can be easily performed.

(Second Embodiment)
The piezoelectric vibrating piece may be a piezoelectric vibrating piece including a vibrating portion that vibrates at a predetermined frequency, a frame that surrounds the vibrating portion, and a connecting portion that connects the vibrating portion and the frame. The piezoelectric device may be formed by sandwiching a frame body between a base plate and a lid plate. A three-layer piezoelectric device formed by superimposing a base plate, a piezoelectric vibrating piece, and a lid plate will be described below. Moreover, in the following description, the same code | symbol as 1st Embodiment is attached | subjected to the part similar to 1st Embodiment, and the description is abbreviate | omitted.

<Configuration of Piezoelectric Device 300>
FIG. 10 is an exploded perspective view of the piezoelectric device 300. The piezoelectric device 300 includes a lid plate 310, a base plate 320, and a piezoelectric vibrating piece 330. FIG. 10 is also an exploded perspective view of the piezoelectric device 400 described in FIG. The piezoelectric device 400 will be described later with reference to FIG.

  The piezoelectric vibrating piece 330 includes a vibrating portion 333 that vibrates when a voltage is applied, a frame body 334 that surrounds the vibrating portion 333, and a connecting portion 335 that connects the vibrating portion 333 and the frame body 334 to each other. A through hole 337 that penetrates the piezoelectric vibrating piece 330 in the Y′-axis direction is formed in a region other than the coupling portion 335 between the vibrating portion 333 and the frame body 334. In the piezoelectric vibrating piece 330, the coupling portion 335 is formed on the + Z′-axis side on the + X-axis side and the −Z′-axis side on the −X-axis side of the vibrating portion 333. Excitation electrodes 331 are formed on the surfaces of the vibration part 333 on the + Y ′ axis side and the −Y ′ axis side, and are drawn out from the excitation electrodes 331 to the corners of the frame body 334 through the connection parts 335. An electrode 332 is formed.

  The base plate 320 is formed with a recess 321 and a joint surface 322 formed around the recess 321 on the surface at the + Y′-axis side. The bonding surface 322 is bonded to the surface on the −Y′-axis side of the frame 334 of the piezoelectric vibrating piece 330 with the bonding material 142 interposed therebetween. Further, castellations 326 are formed at the four corners of the base plate 320, and side electrodes 327 are formed on each castellation 326. A mounting terminal 325 is formed on the surface at the −Y′-axis side of the base plate 320 and is electrically connected to the side electrode 327.

  The lid plate 310 has a recess 311 formed on the surface at the −Y′-axis side, and a bonding surface 312 formed so as to surround the recess 311. The bonding surface 312 is bonded to the surface on the + Y′-axis side of the frame 334 of the piezoelectric vibrating piece 330 with the bonding material 142 interposed therebetween.

  Fig.11 (a) is CC sectional drawing of FIG. In the piezoelectric device 300, the lid plate 310 is joined to the surface on the + Y′-axis side of the frame 334, and the base plate 320 is joined to the surface on the −Y′-axis side. An extraction electrode 332 is extracted from the excitation electrode 331 and is formed up to the corner of the surface on the −Y′-axis side of the frame 334. Further, the mounting terminal 325 of the base plate 320 is connected to the side electrode 327, and the side electrode 327 is electrically connected to the extraction electrode 332 through the castellation 326 and the side surface of the bonding material 142.

  FIG.11 (b) is FF sectional drawing of FIG. The width of the bonding surface 312 of the lid plate 310 is defined as a width WS31, the width of the bonding surface 322 of the base plate 320 is defined as a width WS33, and the width of the frame 334 of the piezoelectric vibrating piece 330 is defined as a width WS35. Further, assuming that the bonding surface 312 and the bonding material 142 are bonded with the width WS32, and the bonding surface 322 and the bonding material 142 are bonded with the width WS34, the width WS32 is narrower than the width WS31, and the width WS34 is the width WS33. Narrower than. Therefore, the bonding material 142 is not formed on the inner peripheral side 312 a of the bonding surface 312. Further, the bonding material 142 is not formed on the inner peripheral side 322 a of the bonding surface 322. The frame 334 and the bonding material 142 are bonded with a width WS35.

<Method for Manufacturing Piezoelectric Device 300>
FIG. 12 is a flowchart showing a method for manufacturing the piezoelectric device 300. Hereinafter, a method for manufacturing the piezoelectric device 300 will be described with reference to the flowchart of FIG.

  In step S601, a piezoelectric wafer W330 is prepared. Step S601 is a step of preparing a piezoelectric wafer W330 including a plurality of piezoelectric vibrating pieces 330.

  FIG. 13 is a plan view of the piezoelectric wafer W330. A plurality of piezoelectric vibrating pieces 330 are formed on the piezoelectric wafer W330. In FIG. 13, a scribe line 163 is shown between adjacent piezoelectric vibrating pieces 330. The outer shape of the piezoelectric vibrating piece 330 is formed in the piezoelectric wafer W330 by forming a through hole 337 by etching, the excitation electrode 331 is formed in the vibrating portion 333, and the extraction electrode is provided in the connecting portion 335 and the frame body 334. 332 is formed.

  In step S <b> 602, the bonding material 142 is applied to the frame body 334. Step S <b> 602 is a step of applying the bonding material 142 to both main surfaces of the frame 334. The bonding material 142 is applied to the surface of the frame body 334 on the + Y′-axis side and the −Y′-axis side by screen printing. Further, the bonding material 142 is not applied to the intersection of the scribe line 163 extending in the X-axis direction and the scribe line 163 extending in the Z′-axis direction on the surface on the −Y′-axis side and around the intersection.

  FIG. 14A is a partial cross-sectional view of the piezoelectric wafer W330 to which the bonding material 142 is applied. FIG. 14A corresponds to the DD cross section of FIG. 13 where the bonding material 142 is applied. The bonding material 142 is formed on the surface on the + Y′-axis side and the surface on the −Y′-axis side of the frame 334.

  FIG. 14B is an enlarged plan view of the surface at the −Y′-axis side of the piezoelectric wafer W <b> 330 coated with the bonding material 142. The bonding material 142 is applied to the entire surface on the + Y′-axis side of the frame 334 of the base wafer W320. On the other hand, the bonding material 142 is also applied to the surface on the −Y′-axis side of the frame 334 of the base wafer W320, but a region 164 where the bonding material 142 is not applied is formed at the intersection of the scribe lines 163. In this region 164, a part of the extraction electrode 332 extracted from the excitation electrode 331 formed on the surfaces on the + Y′-axis side and the −Y′-axis side is formed.

  In step S603, the bonding material 142 is temporarily cured. Step S603 is a temporary curing process. The temporary curing is the same as step S203 in FIG. The bonding material 142 is cured by this temporary curing.

  In step S701, a base wafer W320 is prepared. Step S701 is a step of preparing a base wafer W320 having a plurality of base plates 320.

  FIG. 15 is a plan view of the base wafer W320. A plurality of base plates 320 are formed on the base wafer W320. In FIG. 15, a scribe line 163 is shown at the boundary between adjacent base plates 330. A recess 321 is formed on the surface of each base plate 320 on the + Y′-axis side, and the base wafer W320 is placed at the intersection of the scribe line 163 extending in the X-axis direction and the scribe line 163 extending in the Z′-axis direction. A through hole 326a penetrating in the axial direction is formed. The through hole 326a becomes a castellation 326 after the base wafer W320 is cut. In step S701, the mounting terminal 325 and the side electrode 327 are not formed on the base wafer W320.

  In step S801, a lid wafer W310 is prepared. Step S801 is a step of preparing a lid wafer W310 having a plurality of lid plates 310. As with the lid wafer W <b> 110 shown in FIG. 6, the lid wafer W <b> 310 has a recess 311 and a bonding surface 312 formed on the surface at the −Y′-axis side.

  In step S901, the base wafer W320 and the piezoelectric wafer W330 are bonded. In step S901, the base wafer W320 and the piezoelectric wafer W330 are overlapped, and the bonding material 142 is melted by irradiating the bonding material 142 disposed between the base wafer W320 and the piezoelectric wafer W330 with a laser having a predetermined wavelength. And a first bonding step for bonding the base wafer W320 and the piezoelectric wafer W330.

  FIG. 16A is a partial cross-sectional view of the piezoelectric wafer W330 and the base wafer W320 overlaid on each other. FIG. 16A is a cross-sectional view including the EE cross section of FIG. In the superposition of the piezoelectric wafer W330 and the base wafer W320, the base wafer W320 is superposed on the −Y′-axis side of the piezoelectric wafer W330 so that the scribe line 163 overlaps in the Y′-axis direction. At this time, the region 164 where the bonding material 142 of the piezoelectric wafer W330 is not formed overlaps the through hole 326a of the base wafer W320 in the Y′-axis direction.

  FIG. 16B is a partial cross-sectional view of the piezoelectric wafer W330 and the base wafer W320 bonded to each other. The bonding of the piezoelectric wafer W330 and the base wafer W320 is performed by irradiating the bonding material 142 with the laser 151 from the surface on the −Y′-axis side of the base wafer W320 to melt a part of the bonding material 142 in contact with the base wafer W320. To do. The joining by the laser 151 is the same as step S403 in FIG.

  In step S902, the lid wafer W310 and the piezoelectric wafer W330 are bonded. In step S902, the lid wafer W310 and the piezoelectric wafer W330 are overlapped, and the laser 151 is irradiated to the bonding material 142 disposed between the lid wafer W310 and the piezoelectric wafer W330, thereby melting the bonding material 142 and the lid wafer W310. This is a second bonding step for bonding the piezoelectric wafer W330.

  FIG. 17A is a partial cross-sectional view of the piezoelectric wafer W330, the base wafer W320, and the lid wafer W310 to which the piezoelectric wafer W330 and the lid wafer W310 are bonded. In joining the lid wafer W310 and the piezoelectric wafer W330, first, the lid wafer W310 is superposed on the surface on the + Y′-axis side of the piezoelectric wafer W330 so that the scribe lines 163 overlap each other in the Y′-axis direction. Furthermore, the bonding material 142 is melted by irradiating the bonding material 142 formed on the surface of the frame 334 of the piezoelectric wafer W330 on the + Y′-axis side from the surface on the + Y′-axis side of the lid wafer W310. The joining by the laser 151 is the same as step S403 in FIG.

  In step S903, an electrode is formed on the base wafer W320. In step S903, the mounting terminal 325 and the side electrode 327 are formed on the base wafer W320 so that the side electrode 327 is electrically connected to the extraction electrode 322.

  FIG. 17B is a partial cross-sectional view of the piezoelectric wafer W330, the base wafer W320, and the lid wafer W310 having electrodes formed on the base wafer W320. The electrode formation on the base wafer W320 is performed, for example, by sputtering a metal film on the surface at the −Y′-axis side of the base wafer W320. The metal film is formed, for example, by sputtering a chromium (Cr) film and forming a gold (Au) film on the surface of the chromium film. The metal film formed on the base wafer W320 becomes the mounting terminal 325 and the side electrode 327. The through hole 326a of the base wafer W320 is formed by spreading the metal film over the entire through hole 326a because the surface on the + Y′-axis side is closed by the frame body 334 and the bonding material 142 of the piezoelectric wafer W330. Further, since the through hole 326a is connected to a region 164 where the bonding material 142 on the surface on the −Y′-axis side of the piezoelectric wafer W330 is not applied, the side electrode 327 formed in the through hole 326a is drawn out of the region 164. Also formed on the electrode 332, the side electrode 327 and the extraction electrode 332 are electrically connected.

  In step S904, the piezoelectric wafer W330, the base wafer W320, and the lid wafer W310 are cut. Step S904 is a cutting process. In step S904, similarly to step S404, the wafers are cut along the scribe lines 163 of the respective wafers, so that the piezoelectric devices 300 are individually divided.

<Configuration of Piezoelectric Device 400>
Even in a three-layered piezoelectric device formed by sandwiching a piezoelectric vibrating piece between a base plate and a lid plate, a cutting process can be performed more easily by not forming a bonding material on the scribe line, similarly to the piezoelectric device 200. be able to. Hereinafter, the piezoelectric device 400 that can easily cut the wafer will be described. In the following description, the same parts as those of the piezoelectric device 300 are denoted by the same reference numerals and description thereof is omitted.

  18A is a cross-sectional view taken along the line CC of FIG. 10 as the piezoelectric device 400. FIG. The piezoelectric device 400 differs from the piezoelectric device 300 only in how the bonding material 142 is formed, and the other configuration is the same as the piezoelectric device 300. In the piezoelectric device 400, there is a region where the bonding material 142 is not formed on the outer periphery of the surface on the + Y′-axis side and the surface on the −Y′-axis side of the frame 334 of the piezoelectric vibrating piece 330.

  18B is a cross-sectional view taken along the line FF of FIG. 10 as the piezoelectric device 400. FIG. The width of the bonding surface 312 of the lid plate 310 is defined as a width WS31, the width of the bonding surface 322 of the base plate 320 is defined as a width WS33, and the width of the frame 334 of the piezoelectric vibrating piece 330 is defined as a width WS35. Also, the bonding surface 312 and the bonding material 142 are bonded with a width WS41, the bonding surface 322 and the bonding material 142 are bonded with a width WS42, and the + Y′-axis side and the −Y′-axis side of the frame 334 are bonded to the bonding material 142. Are joined by a width WS43, the width WS41 is narrower than the width WS31, the width WS42 is narrower than the width WS33, and the width WS43 is narrower than the width WS35. Further, in the piezoelectric device 400, the inner peripheral side 312a and the outer peripheral side 312b of the bonding surface 312, the inner peripheral side 322a and the outer peripheral side 322b of the bonding surface 322, the surface on the + Y′-axis side and the −Y′-axis side of the frame 334. The bonding material 142 is not formed on the outer peripheral side 334b of this surface.

<Method for Manufacturing Piezoelectric Device 400>
Also in the piezoelectric device 400, the piezoelectric device 400 can be manufactured by the same procedure as the flowchart shown in FIG. Hereinafter, a manufacturing method of the piezoelectric device 400 will be described with reference to the flowchart of FIG. In the following description, only portions different from the piezoelectric device 300 will be described, and description of portions similar to the method for manufacturing the piezoelectric device 300 will be omitted.

  FIG. 19A is an enlarged plan view of the surface on the + Y′-axis side of the piezoelectric wafer W330 to which the bonding material 142 is applied. FIG. 19A shows a state in which the bonding material 142 is applied in step 602 to the surface on the + Y′-axis side of the frame 334 of the piezoelectric wafer W330 shown in FIG. In FIG. 19A, the bonding material 142 is not formed on the scribe line 163.

  FIG. 19B is an enlarged plan view of the surface at the −Y′-axis side of the piezoelectric wafer W <b> 330 coated with the bonding material 142. FIG. 19A shows a state in which the bonding material 142 is applied in step 602 to the surface on the −Y′-axis side of the frame 334 of the piezoelectric wafer W330 shown in FIG. The bonding material 142 applied to the surface of the piezoelectric wafer W330 on the −Y′-axis side is formed with a bonding material 142 so as to surround the intersection of the scribe lines 163 (see a region 165 surrounded by a dotted line). An extraction electrode 332 is formed in the region 165. In other regions, the bonding material 142 is not formed on the scribe line 163.

  FIG. 20A is a partial cross-sectional view of the lid wafer W310, the piezoelectric wafer W330, and the base wafer W320 to which the piezoelectric wafer W330 and the lid wafer W310 are bonded. FIG. 20A shows a state in which the lid wafer W310 and the piezoelectric wafer W330 in step S902 are bonded. FIG. 20A is a cross-sectional view including the EE cross section of FIG. 15, the bonding material 142 is irradiated with the laser 151 to melt the bonding material 142, and the lid wafer W <b> 310 and the bonding material 142 are bonded. The state is shown. The bonding by the laser 151 is the same as that of the piezoelectric device 300, but the output of the laser 151, the beam diameter, and the like are adjusted in accordance with the width and shape of the formation region of the bonding material 142.

  FIG. 20B is a partial cross-sectional view of the lid wafer W310, the piezoelectric wafer W330, and the base wafer W320 in which electrodes are formed on the base wafer W320. The bonding material 142 formed between the piezoelectric wafer W330 and the base wafer W320 is also formed around the intersection of the scribe lines 163 (see a region 165 in FIG. 19B). Therefore, when the base wafer W320 and the piezoelectric wafer W330 are bonded, the surface on the + Y′-axis side of the through hole 326a of the base wafer W320 is closed with the bonding material 142 and the frame body 334. Therefore, the electrode can be reliably formed in the through hole 326a.

  As described above, the optimal embodiment of the present invention has been described in detail. However, as will be apparent to those skilled in the art, the present invention can be implemented with various modifications and variations within the technical scope thereof.

  For example, in the piezoelectric device 200 and the piezoelectric device 400, it has been described that there is a region where the bonding material is not formed on the outer peripheral side such as the bonding surface of the base plate and the lid plate, but the width of the scribe line cutting allowance by the cutting process is considered. By doing so, it can form so that the area | region where the joining materials of outer peripheral sides, such as a joining surface, may not be formed does not exist.

DESCRIPTION OF SYMBOLS 100, 200, 300 ... Piezoelectric device 101 ... Cavity 110, 310 ... Lid board 111 ... Recessed part 112 ... Joining surface 120, 320 ... Base board 121 ... Recessed part 122 ... Joining surface 123 ... Connection electrode 124 ... Through-electrode 125 ... Mounting terminal 130 , 330 ... Piezoelectric vibrating piece 131, 331 ... Excitation electrode 132, 332 ... Extraction electrode 141 ... Conductive adhesive 142 ... Bonding material 151 ... Laser 152 ... Laser oscillator 153 ... Galvano 161, 326a, 337 ... Through hole 162 ... Connection part 163 ... Scribe line 164 ... Area where bonding material of frame is not applied 321 ... Recess 322 ... Bonding surface 325 ... Mounting terminal 326 ... Castellation 327 ... Side electrode 333 ... Vibrating part 334 ... Frame 335 ... Connecting part

Claims (9)

A piezoelectric vibrating piece that vibrates when a voltage is applied;
A base plate on which the piezoelectric vibrating piece is placed;
A lid plate that is bonded to the base plate and seals the piezoelectric vibrating piece;
A bonding material for bonding the base plate and the lid plate,
The lid plate and the base plate have an annular joining surface having a predetermined width to which the joining material can be applied,
A piezoelectric device in which a width at which the bonding material and at least one of the bonding surfaces of the lid plate or the base plate are bonded is narrower than a predetermined width of the bonding surface. A piezoelectric vibrating piece having a vibrating part that vibrates by application of a voltage and a frame surrounding the vibrating part;
A base plate and a lid plate that are bonded to both main surfaces of the frame body of the piezoelectric vibrating piece, seal the vibrating portion, and are made of glass or quartz;
A bonding material for bonding the frame body and the base plate and the lid plate;
The lid plate, the base plate, and the frame have an annular joining surface having a predetermined width to which the joining material can be applied,
A piezoelectric device in which a width at which the bonding material and at least one of the lid plate, the base plate, or the bonding surface of the frame are bonded is narrower than a predetermined width of the bonding surface.   The piezoelectric device according to claim 1, wherein the bonding material absorbs a laser having a predetermined wavelength, and at least one of the lid plate or the base plate transmits the laser.   The piezoelectric device according to claim 2, wherein the bonding material absorbs a laser having a predetermined wavelength, and the lid plate and the base plate transmit the laser.   The said bonding material is a low-melting-point glass that melts at 350 ° C to 410 ° C mixed with metal particles that absorb the predetermined wavelength or colored with a coloring material that absorbs the predetermined wavelength. Item 5. The piezoelectric device according to Item 4. A piezoelectric device manufacturing method comprising: a piezoelectric vibrating piece that vibrates by application of voltage; a base plate on which the piezoelectric vibrating piece is placed; and a lid plate that seals the piezoelectric vibrating piece to the base plate,
Preparing a plurality of the piezoelectric vibrating pieces;
Preparing a base wafer having a plurality of base plates and a lid wafer having a plurality of lid plates;
Applying a bonding material to the bonding surface of the base wafer or the lid wafer;
A pre-curing step of heating the applied bonding material and pre-curing the bonding material;
A placing step of placing the piezoelectric vibrating piece on the base plate;
A step of superimposing the lid wafer on the base wafer on which the piezoelectric vibrating piece is placed;
A bonding step of irradiating the bonding material with a laser having a predetermined wavelength to melt the bonding material and bonding the base wafer and the lid wafer;
At least one of the lid wafer or the base wafer transmits the laser having the predetermined wavelength, and the bonding material absorbs the laser having the predetermined wavelength and generates heat. Preparing a piezoelectric wafer including a plurality of piezoelectric vibrating pieces having a vibrating part that vibrates by application of a voltage and a frame surrounding the vibrating part;
Preparing a base wafer having a plurality of base plates and a lid wafer having a plurality of lid plates;
Applying a bonding material to both main surfaces of the frame;
A pre-curing step of heating the applied bonding material and pre-curing the bonding material;
The base wafer and the piezoelectric wafer are overlaid, and the base material is melted by irradiating the joint material disposed between the base wafer and the piezoelectric wafer by irradiating a laser having a predetermined wavelength. A first bonding step for bonding the wafer and the piezoelectric wafer;
The lid wafer and the piezoelectric wafer are overlapped, and the bonding material disposed between the lid wafer and the piezoelectric wafer is melted by irradiating the laser to the bonding material, whereby the lid wafer and the piezoelectric wafer are bonded. A second joining step for joining,
The bonding material absorbs the laser and generates heat, and the lid wafer and the base wafer transmit the laser.   The method for manufacturing a piezoelectric device according to claim 6 or 7, wherein the bonding material is made of low-melting glass that melts at 350C to 410C. A cutting step in which the piezoelectric device is individually divided by cutting the lid wafer and the base wafer;
The method for manufacturing a piezoelectric device according to any one of claims 6 to 8, wherein the bonding material is not applied to at least a region of the lid wafer to be cut.